[et-mgmt-tools] ANNOUNCE: Augeas - a configuration API

[Richard W.M. Jones]

On Mon, Apr 21, 2008 at 09:51:47AM +1000, Mike MacCana wrote:
> On Sun, 2008-04-20 at 10:04 +0100, Richard W.M. Jones wrote:
> > On Fri, Apr 18, 2008 at 12:02:15PM +1000, Mike MacCana wrote:
> > > Using 'widely varying formats' is not 'valuable'. It's an unfortunate
> > > accident that wastes everyone's time with various horrible bandaid
> > > solutions, and occasionally makes destroying user data an 'accepted
> > > limitation' of tools like system-config-named.
> > 
> > Different formats suit different uses, and in any case I wouldn't
> > trust the people who would develop this new "super-format" not to do
> > something stupid like using XML.
> > 
> > Rich.
> > 
> 
> Admins don't like XML because vi isn't an XML editor. It's the
> equivalent of Microsoft Word, treating presentation and content like
> they're the same thing. 

No, it because different formats suit different uses.  XML is fine for
people who never learned how to use lex & yacc.  Two large
anti-patterns in this area are XSLT (a programming language) and Ant
(a Makefile-type tool).  Compare XSLT to CDuce (XSLT done right) and
Ant to plain Makefiles.  Also, try converting a short example from
your favorite programming language into XML to see how parsing is
important.

  <for var="f">
    <for-values>
      <value>programming languages</value>
      <value>config files</value>
      <value>specialist DSLs</value>
    </for-values>
    <progn>
      <print format="XML isn't suitable for %s">
        <arg n="0"><subst var="f"/></arg>
      </print>
    </progn>
  </if>

> Config files aren't logically combinations of characters, lines, and
> paragraphs, They're item / value pairs, sections, and subsections.
> 
> This is why I mentioned creating an editor earlier. There's no reason
> why you need to see XML when you edit it. shouldn't be able to say 'jump
> to next subsection, copy this object, paste it three times' in the same
> way we do with lines and paragraphs in vi.

It's plainly ridiculous to create a whole new editor just for editing
a particular form of file.  This editor you're going to write is going
to be better than vi & emacs?  Maybe after thousands of programmers
have worked on it for > 20 years.  In the meantime admins will need to
switch between using your editor for one particular sort of file (a
small subset of configuration files on the system) versus all the
other files on the system.

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
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